xr250r head light really dull!!!!!

[TRANSPORTER]

Hi guys and girls Happy new year to one and all.

XR250R 1999, kick start only UK model (plastic tank)

Ok here goes my headlight bulb has gone really dull, yeah I know our XR's dont have the brightest but mine is seriously bad.
A few weeks ago before christmas whilst riding home i noticed that my main beam was throwing out the amount of beam spread and distance that the dipped beam should of been doing. As for the dipped beam ok it was rideable as it was bright.

I,m using 55w bulbs in the headlight as oppsed to the 35w standard bulbs and have been for a couple of years now with no ill affects.

I have been behind the headlight this evening and changed the bulb but no difference in brightness I also took apart and wd40'd all the connections behind there, (mmm all of six if i remember correctly)

Anyway when the lights are on engine running tail light and number plate light are fine with no drop in brightness, when I rev the engine the headlight bulb doesnt increase in brightness, neither does it dull when i operate a brake or the horn (thus loading the lighting circuit to take away some power).

Any ideas as to what might be causing this problem, could it be as simple as a bad earth or more expensive????????
Cheers for the help and I will let you know if any ideas that come along fix the problem.

[XR Mad]

If its like the 400 the headlight has it own circuit seperate from all the other electrical stuff on the bike
Checking earthing is a good start take the bulb out of the headlight and switch it on when you put main beam on check to see if both fillaments try to light up at the same time they shouldnt earth faults can cause this.

[416cc]

My first thought was to check the headlight earth. Easy to test using a multimeter or run a seperate wire from a known good earth to the headlight bulb & see what happens.

[TRANSPORTER]

ok guys sorry for the delay in replying, I did try the earth route but i could see no noticable change in the brightness, I have looked in my manual and then at my wires and I know my loom is original but my wires dont match up to the colours on the haynes manual, not to worry though.
Now could you tell me if the small finned aluminum type box under the seat that is bolted to the airbox, is this the lighting regulator?
At the moment I have swapped my headlight wire from the feed wire from this and put the headlight wire into the free connector coming out of this box, and I am getting a nice bright headlightm so im guesing im putting a nice voltage throught this wire to the headlight now.
But as before my tail light is unaffected and is happily working away.
Any other ideas, ive been away from my garage and bike as im being a fair weather rider at the moment.

[XR Mad]

Yep thats the ac regulator for the headlight only its located under the tank on mine the dc regulator/rectifier is behind the headlight cowl on mine and provides the power for the horn idiot lights stop/tail and indicators if fitted
Theres allot of different wiring diagrams for the xr but i think the basics are the same

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cheers for the informative replies guys, I am going to have a proper look at her this week and will get to the bottom of the problem, ive been watching a coupkle of xr250r regulators on ebay both going for £36 so i9 might have to go for one of them.
I will post my findings so others can hopefully find a solution in the future if the problem should arise for them.

[TRANSPORTER]

Well its been awhile and I promised to get back to you with my findings, well so far I have traced earth back to the horn and then onto the frame, also up to the coil. Both earth points are clean and free from corrosion, also earthed the bulb seperatly and still dull, so my conclusion is it must be the rectifier thingy under the seat. I am going to rob my mates xr400 of his and see if it makes a difference, if so I shall then spend some of my hard earned on another one, but is there any way of testing these units. Well wish me luck.Oh also i,m after a rear wheel mine has got a crack between two spokes and will need replacing so if anyone has one for a reasonable price??????

[416cc]

I have a feeling that the headlight is run from the AC winding directly off the alternator. In which case I would check the earth from the lighting coil.

As for the rear wheel I would just replace the rear rim as it would be a lot cheaper than a complete wheel.

[waffles]

I have a rim leftover from a rear wheel that was off a 98 xr250 if that's any good for you? Pretty good nick with your usual scuffs from off roading. I'll post you a pic up if you are still interested

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Waffles, really sorry been away for ages do you still have the rear wheel rim, a picture would be ace mate, also what price are you looking for it, as with everything im after a bargain and your after some cash so hopefully we can come to some arrangement, I can pay via paypal instantly aswell ok.